I don't think so, as I have observed people not posting for a long time. This flexibility of HubPages is unique and that is why I like it. Sometimes due to being busy in our real life, we may not be able to spend as much time here, everyday. That may result in lowering Hubber score, but your already posted content keeps the Hub score moving.
You don't have to meet targets here. This flexibility of HP makes it an ideal platform for creative writing. You have the freedom of choice, even regards the subject you want to write. This differentiates it from other sites, for which I have worked before.